With a development of a semiconductor technology, a device number on an IC (integrated circuit) chip is larger and larger. Various circuit modules and function modules, such as a radio-frequency circuit, an analog circuit, a digital circuit, a MEMS (Micro Electronic Mechanical System) device, or a flash memory circuit, which are integrated on one chip, require different supply voltages. For instance, about 1V is required for the digital circuit, a high writing voltage of tens of volts is required for the flash memory, a supply voltage of dozens of volts (even hundreds of volts) may be required for some sensor devices. Moreover, different circuit modules with a same supply voltage even may interact with each other via a power supply line, thus inducing a noise or a distortion, etc. In addition, a feature size of a device is smaller and smaller, the supply voltage is lower and lower, and accordingly a power consumption is continuously increased, thus causing a sharp increase of a working current of the power supply, and a greater resistance loss resulted from a larger and larger influence of a series resistance of interconnections on the chip. Therefore, the on-chip power supply system are required to have higher performances.
According to a conventional method, that a plurality of power supplies with various voltages are inputted directly from outside, which has following disadvantages.
(1) Large numbers of off-chip power components are required, thus causing high cost, susceptible to interference, complicated management of power supply.
(2) Large numbers of bonding pads are required since the plurality of power supplies are required to be inputted into the chip, which will occupy a large chip area and will increase a chip cost.
(3) When the power supply voltage is low and the current is high, a large voltage drop will occur on a resistance of interconnecting wires, which results in a large power loss and a bad heat dissipation.
Therefore, developing a fully integrated on-chip power supply network, which may realize a voltage and current conversion on the IC is of great importance.